1. Field of the Invention
The present invention relates to a system for automatically controlling the deceleration of a moving object in such a manner as to gently stop the object and, more particularly, to a smooth stop control system. The system of the present invention is applicable to any type of machines or devices which must be stopped in a smooth manner, and particularly suitable for use in a machine, such as an automobile, which is designed to carry people and can decelerate more than 3 meters/second.sup.2.
Throughout the specification, the term deceleration is used to represent a negative of a differentiated value (a) of a speed (v) of an object with respect to the time (t), as given below: EQU deceleration=-a=-dv/dt.
2. Description of the Prior Art
According to the prior art, the deceleration control is dependent mostly on a manual operation. For example, a skilled driver controls the degree of deceleration such that the deceleration is relatively high while the speed of the object is still high and becomes low as the speed is reduced, i.e., at the end of a stop.
There are some control systems which automatically control the deceleration until the speed of the object is reduced to a certain low speed, but for the further deceleration, it is controlled manually. Accordingly, this type of control system cannot be called a full automatic deceleration control system.
Some other control systems may automatically control the deceleration until the object completely stops. But generally in this case, the level of deceleration is relatively low and no serious problem arises. In some systems aimed to have a higher deceleration, it is so controlled as to decelerate the object until the speed of the object is reduced to some slow speed, and thereafter, the deceleration is reduced to a very low level. But if the deceleration starts from a fairly high level, there will be an undesirable shock when the deceleration is switched to said low level.